Prosthetic sutureless heart valve

ABSTRACT

This disclosure relates to a prosthetic sutureless heart valve wherein a two-piece snapring is employed in fastening the valve to the heart. The valve has an annular base which contains a check valve and a plurality of pins which pierce the tissue around the valve. The annular snapring fits into the base near the pins to hold the valve and the tissue intact. A smooth, continuous surface is provided for passage of the blood through the valve.

States atent [72] lnventor Ronald C. Hamaker Royal Oak, Mich.

[211 Appl. No. 751,210

[22} Filed Aug. 8, 1968 [45] Patented Apr. 13, 1971 [7 3] AssigneeMichigan Instruments, Inc.

Grand Rapids, Mich.

[541 PROSTHETIC SUTURELESS HEART VALVE 8 Claims, 8 Drawing Figs.

[52] U.S. Cl 3/1, 128/303 [51] lnt.Cl A6lf 1/22 [50] Field of Search128/334, 303; 3/1 (HV); 251/149.1

[56] References Cited UNITED STATES PATENTS 3,130,419 4/1964 Edwards 3/13,416,159 12/1968 Smeloffet a1 3/1 FORElGN PATENTS 1,180,087 10/1964Germany 3/1l-lV 180,750 9/1966 U.S.S.R. 3/1HV OTHER REFERENCES BeallMitral Valve Prosthesis" Surgitool Inc.

Advertisement, The Journal of Thoracic & Cardiovascular Surgery, Vol.55, No. 2, Feb. 1968, Advertising Page 27. 3- ll-lV PrimaryExaminer-Richard A. Gaudet Assistant ExaminerRonald L. FrinksAtt0rney-Price, l-leneveld, Huizenga and Cooper ABSTRACT: Thisdisclosure relates to a prosthetic sutureless heart valve wherein atwo-piece snapring is employed in fastening the valve to the heart. Thevalve has an annular base which contains a check valve and a pluralityof pins which pierce the tissue around the valve. The annular snapringfits into the base near the pins to hold the valve and the tissueintact. A smooth, continuous surface is provided for passage of theblood through the valve.

Patent ed April 13, m1

2 Sheets-Sheet 1 INVENTOR Romp c. HAHAKER BY ,u' MI ATTORNEYS Patented Aril 13, 1971 3,574,865-

2 Sheets-Shut 2 INVENTOR RONALD C. HAMAKER I Y BY PaQMMW /W ATTOR NEYSPROSTIIETIC SUTURELESS HEART VALVE This invention relates to suturelessheart valves. In one of its aspects it relates to a sutureless heartvalve containing an annular shaped base member having a central aperturewith a check valve in the aperture, upwardly projecting pins on the basemember spaced about the outer portion thereof, an annular snapringhaving a diameter sufficient to fit over the projecting pins, and meansto provide a snap fit between said snapring and said base members, thesnapring and the base being so shaped as to form a smooth, continuoussurface through the central aperture and through the snapring.

In another of its aspects, the invention relates to a sutureless heartvalve as has been hereinbefore described, wherein the check valve is aball valve, a lenticular valve, or a leaflet valve.

It is not too uncommon to replace a heart valve with a permanentmechanical valve. The original development of these prosthetic valveswas directed to sewing the valve into the heart tissue. This method,while being suitable in some instances, is a relatively long processwhich requires an extended period of cardiopulmonary bypass andprotection of the heart by coronary profusion or reduced temperatures.It is highly desirable to have the valve placed in the heart as quicklyas possible without suturing.

Cromie, U.S. Pat. No. 3,l43,742 discloses a prosthetic sutureless heartvalve in which an upper and lower ring contain curved pins which projectradially therefrom. A central ring is provided to squeeze the two ringstogether and cause the pins to rotate about a traverse axis to piercethe tissue surrounding the valve and thereafter lock the tissue inengagement with the valve.

The circulatory system is very delicate and important part of the body.If restrictions or rough surfaces appear within the circulatory system,blood clots can sometimes result. In the arteries and veins and otherpassageways through which blood flows. it is desirable to provide assmooth as possible a surface in order to avoid turbulent flow which isconducive to formation of blood clots. Thus, in the construction ofheart valves, the surface over which the blood flows should be arelatively continuous and smooth surface.

I have now discovered a sutureless heart valve which can be rapidlyinstalled in a heart and which, when assembled, has a smooth,continuous, inner surface through which the blood can flow.

By various aspects of this invention, one or more of the following, orother, objects can be obtained.

It is an object of this invention to provide a sutureless heart valvewhich can be quickly installed in a heart passage.

It is a further object of this invention to provide a prosthetic heartvalve having a smooth, internal surface to minimize the possibility ofturbulent flow of blood through the valves.

It is a still further object of this invention to provide a suturelessprosthetic heart valve having a smooth and continuous inner surface tominimize the traumatic effects of prosthetic valves on the circulatorysystem.

Other aspects, objects, and the several advantages of this invention areapparent to one skilled in the art from a study of this disclosure, thedrawings, and the appended claims.

According to the invention there is provided a two-piece prostheticsutureless heart valve. The valve contains an annular shaped base memberhaving a central aperture with a smooth inner surface and with a checkvalve positioned therein. The valve also has pins projecting axially ofthe valve axis on the base and spaced about the outer portion thereof.Tissue is locked into the base structure by an annular shaped snapringwhich has a diameter sufficient to cooperate with the projecting pins onthe base. The annular snapring also has means on the inner portionthereof for snapping into engagement with a cam engaging surface on thebase member. The inner surface of the snapring is so shaped as to form asmooth, continuous path over the snapring and through the centralaperture.

The invention will now be described with reference to the accompanyingdrawings in which:

FIG. 1 is a perspective view of an embodiment of the invention;

FIG. 2 is a sectional view through a base member of the valve shown inFIG. 1 as placed into a heart;

FIG. 3 is a sectional view of an assembled valve shown in part in FIG.2;

FIG. 4 is a sectional view of a modified valve according to theinvention;

FIG. 5 is a bottom view of the modified valve shown in FIG.

FIG. 6 is a side view, partly in section, of the valve shown in FIGS. 1through 3, and a portion of an instrument for holding the valve while itis inserted into the heart;

FIG. 7 is a view similar to FIG. 6 showing the complete instrument forinserting the valve into the heart, and illustrating the method ofinserting the valve into the heart; and

FIG. 8 is an exploded view of the holding and positioning instrumentshown in FIGS. 6 and 7.

Referring now to the drawings, and FIGS. 1 through 3 in particular, anovel sutureless heart valve has a base 2 and a snap engaging ring 18.The base 2 has a plurality of spaced axially extending ball retaininglegs 8 having their outer ends curved inwardly and joined at a centralpoint along the longitudinal axis of the base member. The base alsoincludes a ball valve I0 which is seated against inner annular surface12 of base member 2. The inner annular surface is smooth and provides acentral aperture in the base member. The ball 10 is free to reciprocatewithin the ball retaining legs 8 to open and close the valve. The basecomprises an annular shoulder 14 and an axially and inwardly extendingflange member 16. A base further contains a plurality of axiallydirected prongs 6 spaced about the outer periphery of the base. Thesnapring 18 comprises an annular ring of sufficient diameter to fit overthe projecting pins 6 and has a smooth inner surface 24. Shoulder 20 ofring 18 abuts against shoulder 14 when the ring is snapped in place. Thesnapring has an inwardly and axially extending shoulder 28 whichcooperates with flange 16 of the base member to snap into place.Shoulder 20 is slightly rounded so as to provide a camming surfaceagainst flange 16 in the snap engagement of ring 18 with base 2. Thesmooth inner surface 24 of ring 18 forms a continuous smooth surfacewith upper flange portion 19. The pins 6 fit into an annular recess 21when the ring 18 is snapped into place in base 2.

In operation, the normal valve in a heart is removed, thereby leaving anaperture. The base member 2 is pushed through the aperture and pulledback slightly. Tissue 4 is then pulled over the outer annular recess inbase 2 and over the projecting pins 6. The tissue does not extend overflange 16. The snapring is then pushed into place with the roundedshoulder 20 camming against flange 16. As can be seen from FIG. 3, thebase 2 and the snapring 18 are so shaped as to provide a smooth,continuous surface through the inner aperture of the valve. As can alsobe seen from FIG. 3, the tissue is held in place between the base 2 andsnapring 18 by pins 6.

Referring now to FIGS. 4 and 5, wherein a second embodiment is shown, abase 52 is provided with a bar 58 which retains flexible disc 60, thecheck valve formed by the flexible disc seating against the innerannular portion of the valve. The base 52 also contains a plurality ofaxially projecting pins 56 spaced about the outer periphery thereof. Thebase 52 also contains axially and outwardly extending flange 62 whichhas a smooth, continuous inner surface. The snapring 64 has a roundedshoulder 66 which cams against the flange 62. The inner annular portionof snapring 64 is shaped at an angle to the axial direction at flange 62so that a locking engagement is provided between the base 52 and thesnapring 64. The external diameter of snapring 64 is sufficient to fitover projecting pins 56 of base 52.

The snapring 64 can be provided with a plurality of axially projectingpins extending toward base 52 in intermediate positions between theouter and inner diameter thereof to further aid in holding tissue 4 inplace.

As can be seen from FIGS. 4 and 5, the valve provides a smooth innersurface which mates with the upper snapring to provide a substantiallycontinuous, smooth surface over which the fluid can flow withoutincreasing dangers of turbulent flow.

Whereas the embodiment of FIG. 1 has been described with reference to asutureless valve having a ball valve, it is also within the scope of theinvention to provide other kinds of check valves in combination withrecited structure. Thus, for example, a lenticular valve or the flat,leaflet-type of valve shown in the embodiment of FIGS. 4 and 5 can beprovided. Similarly, the ball valve of FIGS. 1 through 3 could beemployed in place of the leaflet valve of FIGS. 4 and 5.

EXAMPLE A valve of the type shown in the FIGS. 1 through 3 was placedinto the heart of a dog. During the operation. the normal valve in thedogs heart was cut out and replaced by the valve of the invention. Thebase of the valve was pushed through the aperture'in the heart, and thetissue around the aperture was placed over the pins in the base member.The snapring was then placed on top of the valve and the dog was sewnup. The total time required for insertion of the valve was 7 minutes. AnX-ray was taken of the valve, and indicated that the valve wassuccessfully and suitably placed in the heart.

After the dog expired, the heart was removed and dissected. The valvewas firmly intact, and operated successfully.

Referring now to FIGS. 6, 7, and 8, a holding tube 70 having a pluralityof longitudinal slits 72 is employed in holding base 2 in positionwithin the heart. Positioned within the holding tube 70 is a rod 76having attached to the end thereof an expander 74. A drawing tube 78 hasan end member 80 which threadably engages a threaded portion 82 of rod76. Drawing tube 78 has a pair of oppositely spaced holes 92 in which isremovably positioned a turning pin 84.

When the drawing tube 78 is rotated relative to the holding tube 70, forexample in the direction of the arrow shown in FIG. 6, the expander isdrawn into holding tube 72 to expand the end of that tube against theinner wall portion of base 2.

A snapring pusher 86 having a longitudinal slot 88 and an end member 90is provided to push the snapring 18 into fixed engagement with base 2.

In operation, base 2 is positioned on the slotted end of holding tube70. Drawing tube 78 is rotated with the aid of pin 84 until the expander74 has forced the end of holding tube 70 against base 2 to firmlyhold'the same. The base 2 is then positioned in the aperture in theheart and tissue 4 is folded over pins 6. The turning pin 84 is thenremoved from drawing tube 78 and the snapring I8 is placed over drawingtube 78 and holding tube 70 while the two tubes are held in position.The snapring pusher 86 is then placed over the end of drawing tube 78while holding the slotted portion of holding tube 70. The longitudinalslots 88 of snapring pusher 86 are positioned opposite holes 92 ofdrawing tube 78. The turning pin 84 is then inserted throughlongitudinal slots 88 into holes 92. The snapring pusher 86 is thenforced against the snapring by pushing the end 90 of snapring pusher 86,for example with the palm of the hand, while holding the turning pin 84with two fingers of the same hand. In this manner, the snapring 18 issnapped into place on the base 2.

The tube 70 can be removed by the opposite procedure. The snapringpusher 86 is moved away from the heart while holding pin 84 until thepin reaches the end of slots 88. The holding tube 70 can then be heldand the pin 84 is removed. After the snapring pusher 86 has been removedfrom the end of drawing tube 78, the drawing tube 78 is rotated relativeto holding tube 70, with the aid of pin 84, in order to move theexpander 74 out of the end of the holding tube 70. After this has beendone, the holding tube 70 can be removed from the valve.

Reasonable variation and modification are possible within the scope ofthe foregoing disclosure, the drawings, and the appended claims to theinvention without departing from the spirit thereof.

The embodiment of the invention in which an exclusive property orprivilege is claimed are defined as follows:

lclaim:

l. A sutureless heart valve comprising:

an annular-shaped base member having a central aperture therein; valvemeans attached to said base member and operable within said apenure toblock flow through said aperture;

an annular-shaped snapring for joining said base and valve means to thesurrounding heart tissue, said snapring being joined to said base memberthrough a snap fit so that the heart tissue is firmly held between saidring and base, the inner surfaces of said ring and base being so shapedto form a smooth continuous surface over said snapring and through saidcentral aperture; and

a plurality of pins extending, in an axial direction between said basemember and said snapring so that when said snapring is joined to saidbase, said pins pierce said heart tissue to anchor said tissue betweensaid base and ring, said pins being spaced radially from said aperture.

2. A sutureless heart valve according to claim 1, wherein said baseincludes an axially and inwardly extending flange, and said ringincludes an axially and outwardly extending surface in juxtaposedrelationship with said base flange.

3. A sutureless heart valve according to claim 2, wherein said outwardlyand axially extending surface on said ring has a rounded corner forcamming against said base flange during assembly of said valve.

4. A sutureless heart valve according to claim 3 wherein said pins aremounted on said base, and said snapring flange is of sufficient diameterto fit over said pins when said snapring is joined to said base, saidsnapring flange further including an annular recess for receipt of saidpins when said snapring is joined to said base to provide positivelocking of the tissue between the base and ring. 7

5. A sutureless heart valve according to claim I, wherein said valvemeans is a ball and said base is provided with a plurality of spacedlegs extending axially of said base member and having their outer endscurved inwardly and joined at a central point along the longitudinalaxis of said base and enclosing said ball which is reciprocatable withinsaid legs and seats against said annular base member to close off saidcentral aperture.

6. A sutureless heart valve according to claim 1, wherein said valvemeans comprises a movable disc operably adjacent a face of said basemember to block flow through said central aperture and means on saidbase enclosing said disc, said disc being reciprocable in said enclosingmeans to move away from said base to permit fluid flow through saidcentral aperture.

7. A sutureless heart valve comprising, in combination:

an annular-shaped base member having a central aperture therein;

check valve means in said central aperture being attached to said basemember;

an annular shaped snapring;

means attaching said snapring to said base member through a snap fit,the inner surface of said base member and said snapring being so shapedto form a smooth, continuous surface over said snapring and through saidcentral aperture, said attaching means comprising an axially directedflange with an outwardly extending wall on said snapring and an axiallyand inwardly extending flange on said base, spaced from said centralaperture in juxtaposed relationship with said snapring flange, the innerdiameter of said base flange being slightly smaller than the outerdiameter of said outwardly extending wall at opposing positions of saidwall and said base flange; and

a plurality of pins extending in an axial direction between said basemember and snapring spaced from said aperture.

8. A sutureless heart valve according to claim 7 wherein said outwardlyextending wall of said snapring has a rounded edge which is adapted tocam against said inwardly extending flange during assembly of saidvalve.

1. A sutureless heart valve comprising: an annular-shaped base memberhaving a central aperture therein; valve means attached to said basemember and operable within said aperture to block flow through saidaperture; an annular-shaped snapring for joining said base and valvemeans to the surrounding heart tissue, said snapring being joined tosaid base member through a snap fit so that the heart tissue is firmlyheld between said ring and base, the inner surfaces of said ring andbase being so shaped to form a smooth continuous surface over saidsnapring and through said central aperture; and a plurality of pinsextending in an axial direction between said base member and saidsnapring so that when said snapring is joined to said base, said pinspierce said heart tissue to anchor said tissue between said base andring, said pins being spaced radially from said aperture.
 2. Asutureless heart valve according to claim 1, wherein said base includesan axially and inwardly extending flange, and said ring includes anaxially and outwardly extending surface in juxtaposed relationship withsaid base flange.
 3. A sutureless heart valve according to claim 2,wherein said outwardly and axially extending surface on said ring has arounded corner for camming against said base flange during assembly ofsaid valve.
 4. A sutureless heart valve according to claim 3 whereinsaid pins are mounted on said base, and said snapring flange is ofsufficient diameter to fit over said pins when said snapring is joinedto said base, said snapring flange further including an annular recessfor receipt of said pins when said snapring is joined to said base toprovide positive locking of the tissue between the base and ring.
 5. Asutureless heart valve according to claim 1, wherein said valve means isa ball and said base is provided with a plurality of spaced legsextending axially of said base member and having their outer ends curvedinwardly and joined at a central point along the longitudinal axis ofsaid base and enclosing said ball which is reciprocatable within saidlegs and seats against said annular base member to close off saidcentral aperture.
 6. A sutureless heart valve according to claim 1,wherein said valve means comprises a movable disc operably adjacent aface of said base member to block flow through said central aperture andmeans on said base enclosing said disc, said disc being reciprocable insaid enclosing means to move away from said base to permit fluid flowthrough said central aperture.
 7. A sutureless heart valve comprising,in combination: an annular-shaped base member having a central aperturetherein; check valve means in said central aperture being attached tosaid base member; an annular shaped snapring; means attaching saidsnapring to said base member through a snap fit, the inner surface ofsaid base member and said snapring being so shaped to form a smooth,continuous surface over said snapring and through said central aperture,said attaching means comprising an axially directed flange with anoutwardly extending wall on said snapring and an axially and inwardlyextending flange on said base, spaced from said central aperture injuxtaposed relationship with said snapring flange, the inner diameter ofsaid base flange being slightly smaller than the outer diameter of saidoutwardly extending wall at opposing positions of said wall and saidbase flange; and a plurality of pins extending in an axial directionbetween said base member and snapring spaced from said aperture.
 8. Asutureless heart valve according to claim 7 wherein said outwardlyextending wall of said snapring has a rounded edge which is adapted tocam against said inwardly extending flange during assembly of saidvalve.